Two masked men threatened a member of staff during a raid at a petrol station in Mountsorrel.
The thieves entered the Budgens Garage in Granite Way, threatened the worker and then took alcohol, cigarettes and cash before leaving in a black Honda CRV and driving off towards the A6.
The raid took place at about 3.50am on Tuesday and police are appealing for witnesses to come forward.
Detective Constable Dave Rock said: "Thankfully the member of staff was not hurt, but they were understandably shaken the threats made by the two men.
"At the time of the incident the victim waved to the driver of a white van that was passing. We are appealing directly to that driver to come forward. If you drive a white van and normally take that route to or from work then please think back. Were you in the area that day? Did you see anything suspicious? If so please call police immediately.
"Although it was very early in the morning we are hopeful that someone out there will be able to help us. Did you see the incident? Did you see the car described in the area? Do you know who is responsible? If so please get in touch."
Anyone with any information about the incident is asked to contact Det Con Rock by calling 101.
